ON SILK MANUFACTURE IN THE EXHIBITION. 229 



soon exhaust the source of all these riches. What then is that epidemic 

 which has successively extended its ravages over the major part of Eu- 

 rope '? Our French savans have named it ' petrine ' ; Italians call it ' the 

 predominant malady.' Its characteristics seem to vary, and the bitumi- 

 nous spots which at first appear to mark this disease do not always ac- 

 company it, and are not uniformly its most alarming symptoms. But by 

 whatever name it may be called, the epidemic is nevertheless frightful ; 

 entire batches of silkworms die before spinning ; others only spin poor 

 cocoons, the best of which cannot reproduce without bequeathing to 

 their posterity the germ of a deadly and increasing disease. It is thus 

 that the bombyx Mori, of which France and Italy were so proud, and 

 which they had spent ages in producing and improving, has already in 

 great part disappeared. 



" The International Exhibition occurring at so critical an epoch, has 

 interest in this direction to men who desire to trace effects to causes, and 

 who are entrusted with the preparation of the future of production : it 

 is their province to examine, in all its details, the progress made to ward 

 off and subdue a scourge which so cruelly obstructs the rearing of silk- 

 worms. The efforts hitherto made towards this object have taken three 

 very distinct directions. 



" 1st. The spinners requiring, without delay, large quantities of co- 

 coons to supply their factories, have sent out active and intelligent agents, 

 either to buy cocoons or to obtain eggs of all varieties of the bombyx 

 from countries not yet visited with the disease. They have thus created 

 a new industry, that of ' graineurs,' who establish themselves in non- 

 infected districts, where they buy healthy cocoons, which, when developed 

 into moths, are encouraged to breed. They then return to France with 

 a precious supply of eggs, which are sold to our ' educators.' The races 

 which are thus imported are less delicate than our indigenous breeds, 

 and are, perhaps, somewhat coarser in quality ; but they resist the epi- 

 demic more certainly, and produce passably good silk. The greater part 

 of the cases in the Exhibition of Glass XX. of France and Italy, contain 

 remarkable specimens of these varieties of the worm in their first, second, 

 and sometimes third generations. But how long will these races yet 

 continue exempt from the epidemic, the ravages of which are being daily 

 extended ? This measure is evidently only a palliative, the success of 

 which may soon cease. 



" 2nd. Naturalists have endeavoured to find in the bombyx of the 

 palma Christi, which have been imported from India and China, gene- 

 rators of silk less subject to disease and exempt from 'petrine.' The ex- 

 hibitions made by the ' SociSte Impenale d' Acclimatisation ' of Paris, 

 and by M. Guerin Meneville, awaken, in this respect, a real interest, and 

 attract attention. The bombyx Cynthia, also, may acquire at some 

 future time, an immense importance from the food on which it subsists 

 being easy of culture and inexpensive. But, alas ! how far removed is 

 this silk at the present time in quality and quantity from that of the 



